Global statistics

Demography

Total number of rats	49,776 rats
⨽ females	⨽ 25,527 females (51.28 %)
⨽ males	⨽ 24,249 males (48.72 %)

Rats considered as deceased	46,470 rats (93.4 % of all rats)
⨽ declared with known date	⨽ 22,198 rats (47.8 % of deceased rats)
⨽ presumably dead	⨽ 24,272 rats (52.2 % of deceased rats)

Lifespan
⨽ average	⨽ 22.2 months (♀: 22.6 months – ♂: 21.8 months)
⨽ average, infant mortality excluded	⨽ 22.7 months (♀: 23.1 months – ♂: 22.3 months)
⨽ average, accidents also excluded	⨽ 23.5 months (♀: 23.8 months – ♂: 23.1 months)
⨽ maximum	⨽ 4 years, 3 months, 28 days (DS. Cerberus)

Breeding

Total number of ratteries	688 ratteries
⨽ active in the last 2 years	⨽ 37 ratteries (5.38 %)

Average rattery lifetime	916 days (2.5 years)
Average rattery productivity	8.5 litters (45.2 rats)
⨽ as birth place	⨽ 6.7 internal litters
⨽ as other contributor	⨽ 1.7 external litters

Average mother age	233 days (7.6 months)
Average father age	440 days (14.4 months)
Average litter size	6.6 pups (debiased estimation: 10.3 pups)
Average sex ratio	0.987 (about 101 females for 100 males)

Mortality

Median death age	23 months (50 % of rats die before this age, 50 % after)
Death peak	24 months (death occurs more often at this age than any other)
Interquartile interval	16-27 months (50 % of rats die in this age interval)
Leading death category	“Other” (25 % of declared deaths)
Leading death cause	“*Old age, natural death (from 24 month old minimum)” (23 % of declared deaths)

Death categories

Number of recorded deaths	22,198 rats (48 % of rats considered as dead)
By decreasing frequency	* please note that tumours without recorded localization appear as « Autres »

24.54 %	Other
22.58 %	Old age, natural death (from 24 month old minimum)
16.96 %	Unknown cause
12.59 %	Respiratory
7.85 %	Accidents, traumas, poisonings
7.13 %	Neurological (brain, spinal cords, nerves)
2.25 %	Infant mortality (up to 6 week old)
1.49 %	Reproductive system
1.48 %	Eye, ear, mouth, face
1.18 %	Cardiovascular
0.95 %	Digestive
0.73 %	Urinary system (kidney, bladder)
0.26 %	Skin
0.05 %	Muscles and skeleton

Most frequent death causes

Number of deaths with recorded cause	22,198 rats (48 % of rats considered as dead)
By decreasing frequency	* for rats recorded as dead without precise cause, death category is used instead

22.58 %	*Old age, natural death (from 24 month old minimum)
16.92 %	Undetermined cause (known date)
14.26 %	Undetermined tumor (affected organ unknown)
7.55 %	*Respiratory
4.69 %	Domestic accident (crush, door...)
4.53 %	Undetermined infection or abscess
4.44 %	Bronchitis, pneumonia
4.14 %	Stroke
3.13 %	*Other
2.17 %	Virus, epidemic outbreak, immune deficiency (SDA, Sendai, Tyzzer...)
1.91 %	*Neurological (brain, spinal cords, nerves)
1.52 %	Veterinary accident (anesthesia during a minor operation, medical error, etc.)
1.14 %	Fights, injuries, serious bites, subsequent hemorrhage (excluding abnormal hemorrhage)
1.08 %	*Infant mortality (up to 6 week old)
0.93 %	Heart failure, valvular disease
0.77 %	Stillborn
0.65 %	Pituitary tumor
0.6 %	Mammary tumor
0.55 %	Otitis, ear abscess
0.47 %	Complications of gestation or parturition
0.44 %	Renal failure
0.28 %	Facial tumor (excluding Zymbal tumor)
0.27 %	Intestinal obstruction (excluding megacolon)
0.27 %	Lung tumor
0.27 %	Zymbal gland tumor
0.23 %	Digestive tumor (stomach, liver, pancreas, intestines...)
0.22 %	Lack of milk
0.2 %	Epilepsy
0.18 %	Pulmonary edema
0.17 %	Food poisoning
0.17 %	Hereditary megacolon
0.17 %	Uterus infection (metritis, pyometra)
0.15 %	Generalized cancer, leukemia, lymphoma
0.14 %	Other respiratory trouble
0.14 %	Brain tumor
0.14 %	Liver failure
0.11 %	Tooth abscess
0.11 %	Heart attack, infarct, pulmonary embolism
0.11 %	Malformation, hydrocephalus
0.11 %	*Urinary system (kidney, bladder)
0.1 %	Uterine tumor
0.1 %	Heatstroke
0.1 %	Other tumor (salivary, spleen, adrenal, thyroid...)
0.09 %	Suffocation, choking
0.09 %	Dental malocclusion
0.09 %	Falls, fractures, head or spinal cord trauma (excluding fights)
0.09 %	*Skin
0.08 %	Pododermatitis
0.08 %	Facial abscess (excluding teeth and Zymbal gland)
0.07 %	Other heart or vascular problem
0.07 %	Other infant mortality cause
0.06 %	Vaginal prolapse (excluding tumors and postpartum)
0.06 %	Kidney tumor
0.05 %	Other digestive trouble
0.05 %	Sepsis
0.05 %	Hemorrhage (exaggerated relative to the context, coagulation disorder, hemophilia)
0.05 %	Urinary or kidney infection
0.04 %	Skin tumor, skin cancer
0.04 %	Other neurological trouble
0.04 %	Diabetes
0.04 %	Other known cause fitting no other category
0.04 %	Allergy, anaphylactic shock
0.04 %	*Unknown cause
0.04 %	Subcutaneous abscess
0.04 %	Other reproductive system disorder
0.04 %	*Eye, ear, mouth, face
0.03 %	Other head or neck related trouble
0.03 %	Progressive spinal cord damage, degenerative paralysis
0.03 %	Bladder tumor
0.03 %	Euthanasia without medical cause
0.03 %	Digestive hemorrhage
0.02 %	Malnutrition
0.02 %	Other urinary disorder
0.02 %	Other accident or trauma
0.02 %	Digestive abscess
0.02 %	Bone tumor
0.02 %	*Accidents, traumas, poisonings
0.02 %	Brain infection, encephalitis, meningitis
0.02 %	Urethral obstruction, urinary retention, stones
0.02 %	Retro-orbital abscess
0.02 %	*Cardiovascular
0.01 %	Vaginal tumor
0.01 %	Ovarian tumor
0.01 %	Muscle tumor
0.01 %	Other musculoskeletal trouble
0.01 %	Extensive skin infection (pyoderma, bedsores, etc.)
0.01 %	Gastroenteritis, diarrhea
0.01 %	Poisoning (household products, poisons, stolen medicines, etc.)
0.01 %	Glaucoma
0.01 %	Testicular tumor
0.01 %	*Reproductive system
0.01 %	*Digestive
0 %	Retro-orbital tumor
0 %	Preputial gland tumor
0 %	Parasites
0 %	Joint or bone infection, septic arthritis

Most frequent tumours

Number of tumour-related deaths	3,833 rats (17.27 % of rats with known death cause)
By decreasing frequency	* please note that tumour localization could not be recorded before 2023

82.57 %	Undetermined tumor (affected organ unknown)
3.78 %	Pituitary tumor
3.47 %	Mammary tumor
1.64 %	Facial tumor (excluding Zymbal tumor)
1.57 %	Lung tumor
1.54 %	Zymbal gland tumor
1.33 %	Digestive tumor (stomach, liver, pancreas, intestines...)
0.86 %	Generalized cancer, leukemia, lymphoma
0.81 %	Brain tumor
0.6 %	Uterine tumor
0.57 %	Other tumor (salivary, spleen, adrenal, thyroid...)
0.37 %	Kidney tumor
0.23 %	Skin tumor, skin cancer
0.18 %	Bladder tumor
0.13 %	Bone tumor
0.08 %	Vaginal tumor
0.08 %	Ovarian tumor
0.08 %	Muscle tumor
0.05 %	Testicular tumor
0.03 %	Retro-orbital tumor
0.03 %	Preputial gland tumor